import java.sql.*;

public class Hello {
    public static void main(String[] args) {
        Connection connection=null;
        PreparedStatement preparedStatement =null;
                ResultSet resultSet =null;
        //jdbc步骤
       //1.加载驱动
        try {
            Class.forName("com.mysql.cj.jdbc.Driver");
            //2.创建连接
            String url = "jdbc:mysql://127.0.0.1:3306/jdbc?characterEncoding=utf-8";
            connection = DriverManager.getConnection(url, "root", "121311");
           // if(connection != null){
           //     System.out.println("连接成功");
           // }

            //3.写sql
            String sql = "select*from user02;";
            //4.预编译sql
         preparedStatement = connection.prepareStatement(sql);
            //5.执行sql
            resultSet = preparedStatement.executeQuery();
            //6.遍历结果
            while(resultSet.next()){
                int id = resultSet.getInt(1);
                String name = resultSet.getString(2);
                String pass = resultSet.getString(3);
                System.out.println(id+"----"+name+"----"+pass);

            }

        } catch (ClassNotFoundException e) {
            throw new RuntimeException(e);
        } catch (SQLException e) {
            throw new RuntimeException(e);
        }finally {
            //7.关闭资源
            try {
                if(resultSet != null){
                    resultSet.close();
                }
                if( preparedStatement != null){
                    preparedStatement.close();
                }
                if(connection != null){
                    connection.close();
                }

            } catch (SQLException e) {
                throw new RuntimeException(e);
            }

        }


    }
}





















